1 /*
2 * drivers/extcon/extcon-adc-jack.c
3 *
4 * Analog Jack extcon driver with ADC-based detection capability.
5 *
6 * Copyright (C) 2012 Samsung Electronics
7 * MyungJoo Ham <myungjoo.ham@samsung.com>
8 *
9 * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 */
16
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/device.h>
20 #include <linux/platform_device.h>
21 #include <linux/err.h>
22 #include <linux/interrupt.h>
23 #include <linux/workqueue.h>
24 #include <linux/iio/consumer.h>
25 #include <linux/extcon/extcon-adc-jack.h>
26 #include <linux/extcon.h>
27
28 /**
29 * struct adc_jack_data - internal data for adc_jack device driver
30 * @edev - extcon device.
31 * @cable_names - list of supported cables.
32 * @num_cables - size of cable_names.
33 * @adc_conditions - list of adc value conditions.
34 * @num_conditions - size of adc_conditions.
35 * @irq - irq number of attach/detach event (0 if not exist).
36 * @handling_delay - interrupt handler will schedule extcon event
37 * handling at handling_delay jiffies.
38 * @handler - extcon event handler called by interrupt handler.
39 * @chan - iio channel being queried.
40 */
41 struct adc_jack_data {
42 struct extcon_dev edev;
43
44 const char **cable_names;
45 int num_cables;
46 struct adc_jack_cond *adc_conditions;
47 int num_conditions;
48
49 int irq;
50 unsigned long handling_delay; /* in jiffies */
51 struct delayed_work handler;
52
53 struct iio_channel *chan;
54 };
55
adc_jack_handler(struct work_struct * work)56 static void adc_jack_handler(struct work_struct *work)
57 {
58 struct adc_jack_data *data = container_of(to_delayed_work(work),
59 struct adc_jack_data,
60 handler);
61 u32 state = 0;
62 int ret, adc_val;
63 int i;
64
65 ret = iio_read_channel_raw(data->chan, &adc_val);
66 if (ret < 0) {
67 dev_err(data->edev.dev, "read channel() error: %d\n", ret);
68 return;
69 }
70
71 /* Get state from adc value with adc_conditions */
72 for (i = 0; i < data->num_conditions; i++) {
73 struct adc_jack_cond *def = &data->adc_conditions[i];
74 if (!def->state)
75 break;
76 if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
77 state = def->state;
78 break;
79 }
80 }
81 /* if no def has met, it means state = 0 (no cables attached) */
82
83 extcon_set_state(&data->edev, state);
84 }
85
adc_jack_irq_thread(int irq,void * _data)86 static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
87 {
88 struct adc_jack_data *data = _data;
89
90 schedule_delayed_work(&data->handler, data->handling_delay);
91 return IRQ_HANDLED;
92 }
93
adc_jack_probe(struct platform_device * pdev)94 static int adc_jack_probe(struct platform_device *pdev)
95 {
96 struct adc_jack_data *data;
97 struct adc_jack_pdata *pdata = pdev->dev.platform_data;
98 int i, err = 0;
99
100 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
101 if (!data)
102 return -ENOMEM;
103
104 data->edev.name = pdata->name;
105
106 if (!pdata->cable_names) {
107 err = -EINVAL;
108 dev_err(&pdev->dev, "error: cable_names not defined.\n");
109 goto out;
110 }
111
112 data->edev.supported_cable = pdata->cable_names;
113
114 /* Check the length of array and set num_cables */
115 for (i = 0; data->edev.supported_cable[i]; i++)
116 ;
117 if (i == 0 || i > SUPPORTED_CABLE_MAX) {
118 err = -EINVAL;
119 dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n",
120 i - 1);
121 goto out;
122 }
123 data->num_cables = i;
124
125 if (!pdata->adc_conditions ||
126 !pdata->adc_conditions[0].state) {
127 err = -EINVAL;
128 dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
129 goto out;
130 }
131 data->adc_conditions = pdata->adc_conditions;
132
133 /* Check the length of array and set num_conditions */
134 for (i = 0; data->adc_conditions[i].state; i++)
135 ;
136 data->num_conditions = i;
137
138 data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
139 if (IS_ERR(data->chan)) {
140 err = PTR_ERR(data->chan);
141 goto out;
142 }
143
144 data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
145
146 INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
147
148 platform_set_drvdata(pdev, data);
149
150 err = extcon_dev_register(&data->edev, &pdev->dev);
151 if (err)
152 goto out;
153
154 data->irq = platform_get_irq(pdev, 0);
155 if (!data->irq) {
156 dev_err(&pdev->dev, "platform_get_irq failed\n");
157 err = -ENODEV;
158 goto err_irq;
159 }
160
161 err = request_any_context_irq(data->irq, adc_jack_irq_thread,
162 pdata->irq_flags, pdata->name, data);
163
164 if (err < 0) {
165 dev_err(&pdev->dev, "error: irq %d\n", data->irq);
166 goto err_irq;
167 }
168
169 return 0;
170
171 err_irq:
172 extcon_dev_unregister(&data->edev);
173 out:
174 return err;
175 }
176
adc_jack_remove(struct platform_device * pdev)177 static int adc_jack_remove(struct platform_device *pdev)
178 {
179 struct adc_jack_data *data = platform_get_drvdata(pdev);
180
181 free_irq(data->irq, data);
182 cancel_work_sync(&data->handler.work);
183 extcon_dev_unregister(&data->edev);
184
185 return 0;
186 }
187
188 static struct platform_driver adc_jack_driver = {
189 .probe = adc_jack_probe,
190 .remove = adc_jack_remove,
191 .driver = {
192 .name = "adc-jack",
193 .owner = THIS_MODULE,
194 },
195 };
196
197 module_platform_driver(adc_jack_driver);
198
199 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
200 MODULE_DESCRIPTION("ADC Jack extcon driver");
201 MODULE_LICENSE("GPL v2");
202